Scrap blocks for electric furnaces

ABSTRACT

A metal scrap block for use in electric furnaces is of substantially cylindrical configuration and provided in its outer circumferential surface with angularly spaced longitudinal grooves which extend radially inwardly by between about 1/8 and 1/4 of the block diameter.

United States Patent [1 1 Tezuka 1 Jan. 15, 1974 1 4] SCRAP BLOCKS FORELECTRIC 146,092 12/1873 Parmelee 75/44 FURNACES 316,209

[76] Inventor: Kunitoshi Tezuka, 34 7-ch0me,

Minamisuna-machi, Koto-ku, Tokyo, Japan [22] Filed: Dec. 12, 1966 [21]Appl. No.2 601,034

[30] Foreign Application Priority Data Sept. 3, 1966 Japan 41/57944Sept. 10, 1966 Japan 41/59632 Sept. 30, 1966 Japan 41/64315 [52] us. C1..[29/186, 75/43, 75/44 s [51] Int. Cl. B21c 37/00 [58] Field of Search'29/186; 100/240; 75/43, 44

[56] References Cited UNITED STATES PATENTS 140,383 7/1873 Pevey .175/44 4/1885 Westerman 75/44 FOREIGN PATENTS OR APPLICATIONS 404,60810/1924 Germany 75/44 Primary Examiner-L. Dewayne Rutledge AssistantExaminer-J. M. Davis [57] I ABSTRACT A metal scrap block for use inelectric furnaces is of substantially cylindrical Configuration andprovided in its outer Circumferential surface with angularly spacedlongitudinal grooves which extend radially inwardly by between about /8and A1 of the block diameter.

11 Claims, 7 Drawing Figures PATENTEUJAH 15 m4 SHEU 1 0F 2 |NVENTORKUN/TOSH/ TEZUKA PATENTEDJAMSIQM 3785.784

SHEET 2 0F 2 I "1 g FB. 11L

INVENTOIQ KUN/TOSH/ TEZUKA SCRAP BLOCKS FOR ELECTRIC FURNACES Thepresent invention relates to improvements in scrap blocks of iron andthe like to be melted in an electric furnace.

A conventional press machine for shaping metal scrap blocks is composedprincipally of a hollow, cylindrical press casing and pressing means,and scrap blocks shaped up thereby are solid and cylindrical. Anordinary electric furnace, generally in use, is provided with a hollowand cylindrical furnace and a plurality of electrodes to be insertedinto said furnace, so that melting of scraps may be carried out bybringing said electrodes into contact with the upper ends of saidcharged blocks. Therefore, in the melting of said blocks with electricfurnace, the central, axial portion of said blocks is relatively easilymelted but the outer peripheral portion thereof tends to remain unmeltedin a hollow, cylindrical form. Accordingly, in order to make the meltingcomplete, complicated, troublesome processes have been heretofore inpractice: said unmelted portion is cut into several pieces by gascutters or the like; said pieces are dropped down into the molten metalon the furnace bottom; and then the melting is again carried out. Sincethe cutting work is performed near the high-temperature furnace it isvery dangerous for the workers; also, it is a waste of labor to do thecutting and, moreover, it consumes a great deal of oxygen. Otherwise, inthe conventional furnaces, there is a thought to the effect that itshould be desirable to provide more electrodes to use also in thepositions corresponding to said unmelted portions. However, it is notonly difficult in respect to the construction and also undesirable forthe safety of the furnace walls to provide more electrode rods near theinner wall of the furnace,; in addition, it is extremely uneconomical ofpower consumption to increase the number of electrode rods.

The object of this invention is to provide a method of making metalscrap blocks which can be completely melted in electric furnacesefficiently as well as economically and without requiring cutting worksuch as mentioned above.

Metal scrap blocks according to this invention are solid andsubstantially cylindrical, having parallel slots formed on the outerperiphery thereof in the direction of the ge neratrixes. Said blockswill be completely melted, in the melting'process by electric furnace,efficiently and economically on account of the provision of these slots.

The number, depth, cross-sectional shape, etc. of

said slots will be suitably designed to make effective the delivery,melting, etc. of blocks; it is particularly desir able to determine thedepth of slots at about A to Va of the diameter of said blocks and saidcross-sectional shape as trapezoidal, square, triangular, semicircularor in any other form.

Other objects and advantages of the present invention will becomeapparent from the further following description taken in connection withthe appended drawings in which:

FIG. 1 is an oblique view of a metal scrap block;

FIG. 2 is a frontal view of a press machine showing avertically-sectional view of its casing and pressing means;

FIG. 3 is a-plane view of the casing;

FIG. 4 is a bottom view of the pressing means;

FIG. 5 is a partial plane view of another embodiment of the casing;

FIG. 6 is a partial plane view of another embodiment of the casing; and

FIG. 7 is a schematic figure for illustrating the melt ing in anelectric furnace.

ln reference to the drawings, scrap block 1 as shown in PK]. 1 is solidand substantially cylindrical, made with iron scraps pressed and thusshaped, its outer pe' riphery having four slots 2 whose cross-sectionalshape is trapezoidal, formed at equal intervals and in parallel to eachother in the direction of the generatrixes and extending from the oneend 3 to the other end 4; the depth in the diametrical direction of saidslots 2 is about 1/5 of the diameter of said block I.

Said block 1 is completely melted in electric furnace efficiently aswell as economically as the following description will clarify. In FIG.7, said block 1 is inserted into an electric furnace P with its end 3facing upward; electrode rods E are inserted into the furnace from aboveand the lower rod ends are brought down upon the upper end 3 of saidblock 1. Utilizing the requisite electric current, the melting isstarted. The central,

axial portion of said block first begins to melt and the molten metalthereof gathers in the furnace bottom, said axial portion lying in thedirection of extension of said electrode rods. Said melting furtherdevelops gradually and outwardly to reach said slots 2 eventually,whereupon the outer peripheral portion of the block which has hithertotended to remain unmelted in a hollow and cylindrical shape, separatesinto into four pieces C along said slots 2, each of said pieces C thenslipping down by its own weight into the molten metal on the bottomwhere it is naturally all melted.

' x araz agaisrta ras1;;a this iiiventi o ii will naturally andcompletely melt in the electric furnace having no portion left unmeltedat all and therefore said blocks will enable the melting process to becarried out markedly more efficiently in comparison to conventionalblocks, and will also enable a considerable reduction in the electricpower consumption of the electric furnace.

Th s as rhaiiii Efiihbfifisiofsi bisaid"blacks is within the range ofabout A to Vs of the diameter of block will affect said melting andother processes very favorably, because, if said depth is too small, itwill make difficult the separation into pieces of the unmelted portionof said blocks, thus obstructing the efficient, economical and completemelting of the blocks; if said depth is too great, on the other hand, itwill make the blocks too easily breakable, thus decreasing theoperational efficiency inldelivery and transfer of blocks.

Now a press machine for shaping said metal scrap blocks will bedescribed in the following:

The press machine is composedmainly of a press casing and pressingmeans. Referring to FIGS. 2 and 3, the press casing 5 whose one end isentirely open is steelmade and substantially cylindrical, having itsinner surface 6 welded with four ridged steel male dies 7 at equalintervals in parallel to each other in the direction of the generatrixesfrom the casing opening 8 to the bottom 9. The number, diametricalheight of ridges, cross-sectional shape, etc. of said male dies 7 shouldbe suitably determined with a view to making effective the pressing,removal of blocks out of the casing, melting, etc. Saidridge height, inparticular, is about 1/5 of the and a large gear 19 secured to the topof said press disk.

inner diameter of the casing in the foregoing example but it ispreferable to select the effective range of about V: to V8 of the innerdiameter of the casing. The crosssectional shape thereof is trapezoidalin the above example but any other form such as square, triangular,semicircular shapes may be adopted.

Further, a description will be made concerning the pressing means andthe attached devices thereof. As the pressing members of the presentdevice, those which are conventionally known to the public or othervariety which can be thought of in the future may be as well freelyutilized with this invention, but the examples herein shown have adoptedpressing members which comprise a number of spot press rams moved by afluid pressure cylinder such as oil-pressure or hydraulic cyll inder anda rotary press disk having a concavo-convex part on its pressing face.

Iieferring to FIGS. 2, 4 and 5 two oil-pressure cylinders 12 forelevating the rotary press disk 11 are borne vertically by a beam of agate-type frame F and the lower ends of the rams 13 of said cylindersare secured to a supporting block 14. The convex part 15 of said pressdisk 11 is shaped in a cross, the shaft 16 standing on said press diskbeing rotatably and suspendedly borne with bearing. A motor 17 forrotating said press disk is mounted to said supporting block 14, and therotation of the motor is transmitted to the press disk 11 by way of apinion 18 of the drive shaft of the motor Four oil-pressure cylinders 21for lowering all the spot press rams to the pressing position are bornealso by said beam 10. The lower ends of those rams 22 are secured to anannular supporting member 23, on which a number of oil-pressurecylinders 24 for the spot rams are supported vertically. The spot ram 20of each cylinder 24 penetrates, as is so adapted, the supporting ringslidably so as to be able to move back and forth from the underside ofthe ring.

protrudingly at equal intervals on its upper face, the upper end of saidleg being secured to said ram 22. And said each leg 25 has, on itsinside, slots 26 formed as extending from the underside of the ring,said slots being so adapted as to fit into each male die 7 of saidcasing when pressing is effected. Further, in the relation of saidcasing with said pressing means, said supporting ring 23 is devised soas to have its outer diameter made just large enough to be insertableinto said casing 5, and said press disk 11 is devised so as to have itsdiameter made also just large enough to be insertable into said casingwithout touching the male die 7.

On the H66??? there are laid two guide rails 28 extending outwardly fromthe underside of said press means or the pressing portion, and saidcasing is slidably mounted onto said floor in'a manner such that tworail grooves 29 provided underside of said casing fit said rails 28.

In the operation, iron scraps are charged into said casing 5 and saidcasing is moved to its pressing position. Thereafter, by sending ahydraulic fluid into the oil-pressure cylinders 12, 21, said press disk11 and supporting ring 23 are lowered into said casing 5, and therebyprepressing is carried out. Subsequently, in the first place, said pressdisk 11 is elevated back to its original position where the motor 17 isput to work, thus the press disk is rotated slightly, whereafterpressing is carried out repeatedly several times in the same manher. Onthe other hand, each of said spot press rams 20 is projected out andmade recede in repeatedly several times in the same manner by sending ahydraulic fluid into each oil-pressure cylinder 24. By virtue of aseries of these pressing processes, each scrap lump is intermingled andcompressed into a fully compact condition.

W After pressing is through as aforementioned, said casing 5 is movedoutwardly and a block is removed out as shaped up. The resultant blockthus obtained is cylindrical as specified, as is shown in FIG. 1, havingfour slots 2 formed on its outer periphery, and moreover, since eachscrap lump has been intermingled and fully compressed, it is easy indelivery or transfer.

Insaid press machine, the fact that the ridge height of said male die isabout V1 to b of the inner diameter of said casing is desirable inshaping specified blocks. In other words, if the ridge height is toohigh, easily breakable blocks will be shaped up disadvantageously, inaddition to its becoming an obstacle in the pressing; if the ridgeheight is too low, it will be impossible to shape blocks which are ableto be completely melted efficiently as well as economically.

According to kinds, material properties of metal scraps to be disposed,or construction of the pressing means, or other conditions, there'willoccur occasions wherein the aforementioned male dies must be replaced byother dies having ridge height, crosssectional shape, etc., differingfrom said male dies. To cope with such a necessity as this, a presscasing which is removably provided with male dies is furnished herewith.Referring to FIG. 6, there are provided opposedly one each or moreprojections 30 as supporting means on both sides of the position on theinner wall 6 of the casing wherein a male die is to be set in. If a maledie 7a is fitted between said opposing projections with its base,circumferentially shifting thereof will be hampered advantageously bysaid supporting means; there will be no occurrence of any obstruction inthe scrap charging and also in the pressing operation but the sameobject as the foregoing example will be achieved. In this case, it ispreferable to make the inner surface 6 of said casing tapered gentlytoward the bottom, forming a gentle incline. As such supporting means,further, there can be employed a variety of means such as means forfixing male dies to the casing with screws.

"w'itsaarsiaisu gsng'aezs grsviaea iris possible as well to achieve thesame object of this invention, as in the foregoing examples, with apress casing which is composed of said male die 7a just standing againstthe inner surface 6 casing in a specified position of the as is shown inFIG. 7. In such a casing, it is necessary to have the inner surface 6 ofsaid casing inclined as aforementioned.

In the press casing provided with said removable male dies orstanding-type male dies, it is possible to use male dies 7amanufacturing of other material such as wood that is combustible at atemperature lower than the melting point of metal scraps. In this case,when blocks are removed from the casing after shaping them up, it mayoccur that a block is removed together with the male die 7d which ismade of wood and has clung to a block such as mentioned abovejthe maledie may either be removed off the block and again used, or

be put into the electric furnace together with the block and be burnedup while the block is melted away.

What is claimed is: I

- l. A metal scrap block for use in an electric furnace, said blockconsisting of at least substantially compacted metal scraps having incross-section a substantially cylindrical portion and a substantiallyconical portion converging gradually in a direction towards one axialend of said block, provided with a plurality of circumferentially spacedaxial grooves extending from the periphery of said block at leastsubstantially radially inwardly towards but short of a center portion ofsaid block, said center portion being substantially solid,- said grooveshaving a length approaching that of said block, so that, when said blockis melted from the center in radially outward direction, the groovedannular outer portion of the block separates along the respectivegrooves into segments which collapse radially inwardly.

2 A metal scrap bloclc as defined in claim ll, wherein said grooves areof constant cross-section.

3.'A"iii tal s'cisabraeie'marsezrmiaMiriam said grooves converge incross-sectional areas in direction radially inwardly of said block.

' 4.A"asar'scia smsak'asazfisamaaira Eli/Herein said block has apredetermined diameter, and wherein said grooves have a depth whichcorresponds to between substantially and A of said predetermineddiameter.

from said periphery inwardly towards the center of said block,

said grooves approaching the length of said block and being dimensionedso that, when said block is disposed in the melting chamber of anelectric furnace and melting electrodes are advanced in said chamberaxially of said block toward said center portion so as to melt the sameand in so doing to enter into and hollow out said block,

the remaining unmelted outer annular portion of the block in which saidgrooves are provided will separate along the inner boundaries of therespective grooves into individual segments which will collapse undertheir own weight in radially inward direction so as to come within themelting effectiveness range of said electrodes to be melted by the same.

6. A metal scrap block as defined in claim 5, said grooves having across-sectional configuration which converges in direction towards saidcenter of said block.

7. A metal scrap block as defined in claim 5, said grooves having across-sectional configuration which is constant in direction towardssaid center of said block.

8. A metal scrap block as defined in claim 5, wherein said outer annularportion is comparatively narrow.

9. A metal scrap block as defined in claim 5, said block having apredetermined cylindrical diameter; and wherein said grooves have adepth in direction towards said center which corresponds to betweensubstantially /8 and A of. said predetermined diameter.

10. A metal scrap block as defined in claim 5, said block having apredetermined cylindrical diameter; and wherein said grooves havea'depth in direction towards said center which corresponds to about 1/5of said predetermined diameter. I

11. A metal scrap block as defined in claim 5, wherein said block isadapted to rest on said frustoconical end portion upon being melted inthe melting chamber of an electric furnace.

2. A metal scrap block as defined in claim 1, wherein said grooves areof constant cross-section.
 3. A metal scrap block as defined in claim 1,wherein said grooves converge in cross-sectional areas in directionradially inwardly of said block.
 4. A metal scrap block as defined inclaim 1, wherein said block has a predetermined diameter, and whereinsaid grooves have a depth which corresponds to between substantially 1/8and 1/4 of said predetermined diameter.
 5. A metal scrap block to bemelted in an electric furnace, being composed substantially of a solidcenter portion and an outer annular portion having in cross-section asubstantially cylindrical main portion and a frusto-conical end portionwith a diameter converging from said cylindrical portion, said outerportion being provided with a plurality of circumferentially spacedaxial grooves extending from said periphery inwardly towards the centerof said block, said grooves approaching the length of said block andbeing dimensioned so that, when said block is disposed in the meltingchamber of an electric furnace and melting electrodes are advanced insaid chamber axially of said block toward said center portion so as tomelt the same and in so doing to enter into and hollow out said block,the remaining unmelted outer annular portion of the block in which saidgrooves are provided will separate along the inner boundaries of therespective grooves into individual segments which will collapse undertheir own weight in radially inward direction so as to come within themelting effectiveness range of said electrodes to be melted by the same.6. A metal scrap block as defined in claim 5, said grooves having across-sectional configuration which converges in direction towards saidcenter of said block.
 7. A metal scrap block as defined in claim 5, saidgrooves having a cross-sectional configuration which is constant indirection towards said center of said block.
 8. A metal scrap block asdefined in claim 5, wherein said outer annular portion is comparativelynarrow.
 9. A metal scrap block as defined in claim 5, said block havinga predetermined cylindrical diameter; and wherein said grooves have adepth in direction towards said center which corresponds to betweensubstantially 1/8 and 1/4 of said predetermined diameter.
 10. A metalscrap block as defined in claim 5, said block having a predeterminedcylindrical diameter; and wherein said grooves have a depth in directiontowards said center which corresponds to about 1/5 of said predetermineddiameter.
 11. A metal scrap block as defined in claim 5, wherein saidblock is adapted to rest on said frusto-conical end portion upon beingmelted in the melting chamber of an electric furnace.